The present invention relates to navigation systems and more particularly the present invention relates a feature provided by a navigation system to advise a driver about the proper maneuver to make at an intersection as the intersection is being approached.
Navigation systems provide useful features, such as calculating a route to a desired destination and providing guidance for following the route. In order to provide these features, navigation systems use geographic data that include information about the locations of roads and intersections, estimated travel times along road segments, the speed limits along roads, etc. Using these kinds of geographic data, programming algorithms included in navigation systems can find an optimal (e.g, fastest or shortest) route to a specified destination.
Although navigation systems provide useful features, there still exists room for improvements. One area in which there is room for improvement relates to how a navigation system provides route guidance to a driver. When providing route guidance, it is preferable that a navigation system provide clear, unambiguous instructions that are easily understandable by the driver, but not distracting.
One type of instruction that navigation systems are required to provide is advice about making turns. As an example, one approach employed by an exemplary type of navigation system to indicate an upcoming required turn maneuver is described in connection with FIGS. 1-4. FIG. 1 shows a vehicle 10 traveling along a road 12 in the direction indicated by the arrow 13. The vehicle 10 is traveling toward an intersection 14. According to this example, a vehicle navigation system 15 located in the vehicle 10 has calculated a route and is providing guidance to the driver to follow the route. According to the calculated route, a turn should be made at the intersection 14 onto the road 16. FIG. 2 illustrates a user interface 20 of the navigation system 15 located in the vehicle 10. The user interface 20 includes input controls 24, which may include a keypad, buttons, a toggle, etc. The user interface 20 also includes a display screen 26. The navigation system 15 provides route guidance using visual instructions portrayed on the display screen 26. The route guidance may include textual instructions 28, e.g., xe2x80x9cRIGHT TURN AHEAD.xe2x80x9d The route guidance may also include a graphic 30, e.g., an arrow, to indicate that a turn is required ahead. The navigation system 15 may also provide audible instructions or an audible reminder, e.g., a chime sound, that accompanies the presentation of visual route guidance information on the display screen 26.
In the navigation system 15 shown in FIG. 2, the route guidance also provides a xe2x80x9cprogress barxe2x80x9d 32 to indicate an upcoming required maneuver. The xe2x80x9cprogress barxe2x80x9d 32 is a rectangular graphic that the navigation system displays on the display screen 26. The progress bar 32 first appears as an empty vertical rectangle when the vehicle is a predetermined time (e.g., 10 seconds) or distance (e.g., 100 meters) from the intersection at which the required maneuver is to be made. As the vehicle approaches the location of the required maneuver, the progress bar 32 progressively xe2x80x9cfills in.xe2x80x9d The xe2x80x9cfilling inxe2x80x9d is indicated by a change of color, i.e., the xe2x80x9cemptyxe2x80x9d progress bar progressively becomes xe2x80x9cfull.xe2x80x9d A comparison of FIGS. 2 and 4 illustrates operation of the progress bar 32. FIG. 2 shows the progress bar 32 when the vehicle 10 is at the location indicated in FIG. 1. As shown in FIG. 2, the progress bar 32 is partially filled in, as shown at 34, indicating that there still is some distance to go to the required maneuver. FIG. 4 shows the progress bar 32 when the vehicle 10 is at the location indicated in FIG. 3. As shown in FIG. 4, the progress bar 32 is almost completely filled in, as shown at 36, indicating that the vehicle is immediately at the location at which the required maneuver is to be made.
As illustrated by the foregoing example, advice about making a turn can be relatively easy if the road geometry is simple, i.e., there is only one road onto which the turn can be made. However, if the road geometry is complex, it can be difficult to provide clear, unambiguous instructions. For example, there may be another road close to the road onto which the required turn is to be made. FIG. 5 shows an example of such a complex road geometry. When there are two roads close together onto which the driver can turn, it can be difficult for the navigation system to provide the driver with clear, unambiguous instructions that indicate onto which of the roads the turn should be made. The driver may see both roads and not know which road to take, even with the visual and audio instructions, such as the progress bar, provided by the navigation system. If the instructions are not clear, the driver may mistakenly turn onto the incorrect road.
With some navigation systems, a map can be displayed on the display screen. The map may provide some context to the driver. For instance, the driver can see from the map that there are two possible turns close together and that the second turn is the one to be taken. Unfortunately, a map display can sometimes present too much information for route guidance. For example, the map should be drawn to scale, the vehicle position and movement should be depicted, the shapes of the roads should be represented accurately, nearby roads should be depicted even if they are not relevant to the turn to be taken, and map orientation should be correct. In addition, with a map display, street names should be displayed. However, street names may be difficult to read. Further, it may be difficult to associate street names with the proper roads on the navigation system map display, especially if the two roads are close together. All these factors may make it difficult to provide clear, unambiguous route guidance with a navigation system map display when a required maneuver is at a complex intersection.
Accordingly, there exists a need to provide better route guidance with a navigation system.
To address these and other objectives, the present invention comprises a feature provided by a navigation system to provide guidance to a driver of a vehicle. The feature comprises multiple progress bars displayed on a display screen of the navigation system. The multiple progress bars feature is displayed when the vehicle is approaching a location at which a maneuver, such as a turn, onto a road is to be made and another road is close by and might be confused with the road onto which the maneuver should be made. One of the multiple progress bars represents the vehicle""s approach toward the road onto which the maneuver should be made and the other of the multiple progress bars represents the vehicle""s approach toward the road not to be taken. As the vehicle approaches both roads, the progress bars are updated indicating the vehicle""s relative approach to both the road onto which the maneuver should be made and the road not to be taken. The multiple progress bars feature provides meaningful information to the driver in a clear and unambiguous way, thereby assisting the driver to make the proper maneuver.